'Competing British police forces' harmed Madeleine McCann search

British detective chief inspector Andy Redwood works with a Portuguese police officer during searches as part of the investigation into Madeleine McCann's disappearance. Photograph: Filipe Farinha/Getty Images

The investigation into the disappearance of Madeleine McCann was hampered because British police forces competed against one another, according to the author of a secret Home Office report.

Relations with Portuguese authorities were damaged as UK agencies clamoured to get involved in the high-profile case, leading to warnings that Britain should not act as a "colonial power".

Jim Gamble, the former head of the Child Exploitation and Online Protection Centre (CEOP) and the author of the report, also said the government had not learned from its mistakes, saying that it "does not understand the complexities of child abuse".

His unpublished report, which was commissioned by former home secretary Alan Johnson in 2009, also said the decision to put the McCanns' local force, Leicestershire constabulary, in charge of the operation was a mistake because it was ill-equipped to deal with such a wide-ranging investigation.

Although the report was never made public, it led to the reopening of the investigation in 2011 by the Metropolitan police, according to Sky News, which has been briefed on the contents of the document.

Gamble said that competition between police chiefs had a long-term negative effect on the McCann case.

He told the Guardian that agencies developed an "organisational arrogance" in the rush to help.

He said: "Each one thought that their agency would bring the best to bear on this. We were all guilty.

"Everyone came with best intentions," he told Sky News. "That created a sense of chaos and a sense of competition, people putting their hand up and wanting to help, and in many instances, in my opinion, wanting to be seen to help.

"If we look at it honestly, there were some in leadership roles who wanted to represent their organisation, to be seen to take a lead role and to be seen to provide critical input in this – and that made it difficult for a small, regional force like Leicestershire."

He went on: "I've no doubt relationships from the outset with the Portuguese were impacted by it and I think that had a long-term negative effect on the investigation.

"I think to this very day the Met investigation team that's engaged now are still having to manage and massage that relationship and perhaps, to be fair to the Portuguese, mend some fences that were trodden on in the early days."

Within weeks of Madeleine's disappearance in May 2007, Scotland Yard, the National Police Improvement Agency and CEOP had all given advice to Portuguese police.

The Crimestoppers charity published a separate appeal hotline and No 10, the Home Office and the Foreign Office were all demanding briefings from the various agencies.

Gamble explained that the Portuguese police's initial response to the case was chaotic and haphazard. He said this was "alien to the more structured police you would expect here in the UK. There was not a sense of order".

"In the first instance, the parents should be your number one suspects," he told Sky.

"In most cases, in the first few golden hours, as you collect evidence, you can then rule them in or out.

"And that was one of the huge flaws in this – people didn't focus on clearing the ground beneath their feet in those chaotic first few hours that led into the haphazard first few weeks.

"When I carried out the scoping review there was no evidence that some of the critical information and the analysis of which could have led to intelligence and to leads had been followed up."

However, Gamble said that lessons had not been learned from the McCann investigation because Theresa May had snubbed calls for a national resource to deal with child exploitation.

He told the Guardian: "CEOP was something that was created by the Labour government, so it was something that had to be changed by the coalition government. I think it was an act of political vandalism.

"The home secretary didn't understand what she was doing when I met with her. I asked her to explain her rationale for going against the lessons that had been learned.

"She couldn't give me a single answer. She couldn't utter a single word across the table to explain why she thought this was a good idea. But they pushed on anyway."

Following the spate of recent child abuse scandals, Gamble accused the government of failing to act sufficiently to tackle the issue.

He said: "In the face of Rotherham; in the face of over 500 coming forward over Savile; in the face of everything we know we don't know enough about, we need a credible overarching review. And the truth is, we haven't got it."

He has refused to release the full details of the report's findings, saying it was only ever intended to be an internal review.

The Home Office, which declined to release the report under Freedom of Information laws, declined to comment on the report, but said: "We remain committed to supporting the search for Madeleine McCann."

But Gamble believes that the McCann investigation will eventually be solved, despite the setbacks. "Someone knows," he said.

"I genuinely believe that we will find out what happened in my lifetime. Relationships, loyalties change, and at some stage some person will come forward."